New Triplet Lacing hub option

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TheKaiser
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by TheKaiser

RussellS wrote:
TheKaiser wrote:in the article they say triplet lacing won't work with "[i]offset rims


Doesn't offset rims eliminate all the reasons for triplet lacing and other nonsense? Offset rims get the spokes almost equal in length and equal in tension on both sides of the rim. My offset rims have pretty symmetrical spoke angles on both sides. And pretty equal tension on both sides.



Yes, as Ergott said above, very few offset rims come anywhere close to building a symmetric rear wheel, they just reduce the huge imbalance somewhat.

bm0p700f
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by bm0p700f

A 2mm offset on the rim does not equalise spoke tension, not even close. It does improve the situation though. With a proper 2:1 hub you get a tension balance of about 70%. Adding an offset rim improves on that alot.

I should know i have built test wheels and the predictions have been confirmed. As ergott has said it is geometry. Maths does not lie.

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F45
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by F45

Also in the geometry is the evidence that 2:1 is not more laterally stiff than 1:1 (for same number of spokes), even if you push the nds flange out to 50mm. I argued against bm0p on this point in the past...and lost. So I did not forget.

bm0p700f
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by bm0p700f

erm well here is some maths.

Lateral wheel stiffness is made up of a bunch of factors like spoke count, spoke diameter (for round spokes), spoke stiffness. All these factors are products and therefore are fixed for a particular wheel. Lets call this factor A.

The other term is bracing angle and spoke length.

(cos^2(bracing NDS))/spoke length + (cos^2(bracing DS))/spoke length

this term can be done as a ratio for the 2:1 vs normal hub to get relative stiffness.

I have a set of 2:1 hubs made by royce. centre to flange DS =17mm for the nds =46mm. PCD = 46mm

A normal set of hubs have 17mm/37mm flange to centre and PCD of 46mm
ERD =280mm no offset

bracing angle normal are 3.4 deg/7.3 deg for 2x 24 spoke lacing.
bracing angles for 2:1 are 3.4 deg/9.8 deg for 2x DS and radial NDS.
I dont think I have made a mistake in my logic.
plugging the number in I find the 2:1 laced hub is 0.8% stiffer. i.e not stiffer but not less stiff either. I hope that settles it.

I can't even remember the discussion or who said what nor do I care now. The above is what it is and I believe that.

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ergott
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by ergott

The difference being that the 1:1 hub is more likely to have spokes go slack on the NDS due to insufficient tension. With DS spokes at a typical 120kgf your NDS is about 55kgf (non offset rim).

With lower spoke counts and stiffer rims it's easier to have isolated loads drop the tension on said wheel to the point of slack spokes. The solution is more spokes and/or heavier gauge spokes on the drive side, but this being WW no one wants to hear that;-)

When I've built up proper triplet hubs I use 8 heavier gauge spokes on the NDS to improve the rim support on that side.

The better tension balance without reducing lateral stiffness is the essential reason for the pattern. If you try to reduce the tension imbalance by reducing the NDS flange spacing on a 1:1 wheel you lose a lot of lateral stiffness.

lactatehate
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by lactatehate

ergott wrote:$500 for a pair of WI hubs?!?

Okay. Glad I already have a set of the triplet hubs. :roll:

Image


Any chance you could explain more about the rim, hub, lacing & spokes in the photo'ed wheel?
(message if you prefer)

Regards

David

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ergott
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by ergott

That's a Pacenti release of the triplet hub that White Industries made. They made their first hub collaborating with Troy Watson many years ago.

The rim I used is a Pacenti V1. He had 27 spoke rims drilled so that they follow a 36 spoke spacing, but skip every 4th spoke hole. For this build I used Pillar Ti bladed spokes for the right side and Sapim CX-Ray spokes for the left. It was bit experimental in spoke choice just to see if I would like it. Honestly I don't have a lot of miles on this wheel since I've had a bunch of other projects going on. I did make the same build for my riding buddy using all CX-Ray spokes. He's been riding it a lot with great results.

The Martindale will be the 3rd release of basically the same hub from WI and they are charging the most money for it. It will be a nice hub.

Once thing I've noticed about all the triplet specific builds I've done. You are forced to use a straight drilled rim (spoke holes can't angle to one flange). I've yet to see a rim that angles the holes for the triplet pattern. This results in a rather extreme angle that the spokes exit the NDS nipples since the left flange is pushed so far out. I'm keeping an eye on my friend's build for any premature spoke breaking, but don't have enough long term experience to say it will or will not fail sooner than a standard build.

Here are a couple of builds I've done.

Troy's second generation hub manufactured by Industry 9. Pacenti rim again.
Image

This hub never made it into production as far as I know (different company).
Image
Image

bm0p700f
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by bm0p700f

This is why when I get Miche do my hubset I will get rims drilled specifically for the lacing to get around the problem ergot has mentioned. I have done my set with royce 2:1 hubs (a cliff special with titanium flanges) also with a centre drilled pacenti V1 rims. I did another set with a Miche SWR 2:1 hub this year with a Kinlin XR31T. Angles for the NDS are a bit steep but it does not seem to be a problem either.

Still if I can pony up for rims drilled specially for this lacing pattern (10 degree NDS bracing angle) then all the better.

Image
Image
Image
Last edited by bm0p700f on Tue Oct 25, 2016 9:34 pm, edited 1 time in total.

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by kavitator

You must take better pictures of Royce wheelset :roll:

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by sugarkane

whats wrong with blown out, of focus photos :lol:

bm0p700f
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by bm0p700f

The wheels are dirty and in the garage. Not photo ready. Besides whenever I want to take photo's the light is always bad. When I am not working I am riding or sleeping. No time for photo's I leave that to folks who ride less, work or sleep less.

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ergott
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by ergott

bm0p700f wrote:No time for photo's I leave that to folks who ride less, work or sleep less.


That's being judgmental for no reason. You have no comprehension of anyone's life to come to that conclusion. It's also a lame thing to try and brag about.

By the way, the fact that I take photos with some effort is because I take pride in what I do. It reveals the level of detail I put into everything.

Here's an equally lame conclusion I could come to. What else do you do half assed besides taking pics?

:beerchug:

bm0p700f
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by bm0p700f

I am not sure how you managed to get offended by this ergot, I did not mean anything I wrote as an insult. Workless is a good thing I work to much. I ride too much so riding less is a good thing. Sleep less well that not a good thing but I dont sleep enough anyway. I am not a photographer. Never been able to take a good one it not about pride it is about having a good camera and decent lighting where you take pics, I have neither which is why I now get a professional photographer to wheel shots. now who's making judgements.

I mean to cast aspertions on other things I do by my lack of photographing ability is a bit much. Do you think I am thick because I misspell words miss them out e.t.c or do you think it a lack of attention to details. Maybe it is dyslexia instead.

Ergot you are probably a good wheel builder but you photography does not tell me that that tells me who can compose a picture, have a decent camera and decent lighting. Those are the only judgements anyone can make from your pics. Anything else is conjecture and it is conjecture and speculation which causes half of the mess the world is in. the other half is people acting on the conjecture and speculation. That is another matter but you get my point.

I am not taking anything written to heart by the way.

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ergott
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by ergott

Reread my post more carefully. I'm telling you that assuming that people that take nice photos don't work/ride as much as you is silly. It came off as conceited and like some sort of "Johnson" measuring statement that you are better because of your lack of attention to photography.

I then took your train of thought and used it against you and called the results of my assumption equally lame, not that I actually came to that conclusion.

bm0p700f
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by bm0p700f

we have strayed a bit off topic.

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